Circuit arrangement for towing trailer - supplies additional current to tractor direction indicator lamps after detection of failure of corresp. trailer lamp

摘要

The towing vehicle has a flasher unit (19) linked to the direction indicator switch (18) and a circuit (11) with plug-and-socket connection (13,12) to the flashing indicator lamps (16c,17c) on the trailer. These lamps are operated via a driver circuit with high input impedance. In the event of failure of a trailer lamp, the circuit (11) supplies the tractor lamps (16a,16b,17a,17b) with an additional fault current of approximately equal strength by actuation of relay or semiconductor switch. ADVANTAGE - Operating current of flasher unit is reduced in fault conditions signalled by change of frequency.